1. Field of the Invention
This invention relates to an outboard motor, particularly to an outboard motor equipped with both an internal combustion engine and an electric motor for driving the propeller, namely, a hybrid outboard motor.
2. Description of the Related Art
The hybrid outboard motor is a well-known type of outboard motor that has two sources of power for driving the propeller, an internal combustion engine and an electric motor. As taught by Japanese Laid-Open Patent Application No. Sho 59(1984)-230894 (particularly page 2, upper left column, lines 9 to 13, and FIG. 1), for example, the hybrid outboard motor is typically equipped with a first output shaft connected to the engine for transmitting its output to the propeller and a second output shaft connected to the motor for transmitting its output to the propeller, and the first and second output shafts are simply connected in tandem.
From the viewpoint of operating ease and portability, an outboard motor is preferably small and light in weight. However, the configuration taught by the reference does not enable adequate size and weight reduction because the space occupied by the first and second output shafts is proportional to their combined lengths.